docs: def animate_pendulum(self, m,  path="anim_npendulum"):
          """This function generates few images at different instants in order to animate the pendulum.
  
          ..note:: this function destroys and creates the folder :anim_npendulum:.
          """
  
          if os.path.exists(path):
              shutil.rmtree(path)
          os.makedirs(path)
  
          for t in range(0, 1000, 32):
              ax = axes()
              self.plot_npendulum(ax, m, t)
              savefig(os.path.join(path, "{}.png".format(t)))
              clf()